How do I check my components for damages from a (probably) fried, cheap, PSU?

[souhiba132]

So basically, totally unknown to my stupid self, I've been running my computer with an underpowered PSU for nine months and now it has started to smell like burning plastic.

Instantly noticing the smell during my gaming, I instantly Alt+F4'd the game, turned off the computer, and inspected the inside. The motherboard didn't seem to have any bloated capacitors (also the computer didn't smoke nor did it catch on fire, it turned off properly with no problems too), but the smell really did stick to the whole computer.

So now I'm kind of sure that it's the PSU and I'm planning on replacing it with a decent one.

So with that in mind and also TL;DR,
How do I check my other components (GPU, CPU, Fans, Mobo, and HDD) for damages from a (probably) fried, unknown brand PSU, that's been powering my computer for nine months despite being underpowered?

 

[USAFRet]

Only way to really tell is to replace with a known good one, and see what happens.

 

[jankerson]

Yup, only way is to get a new PSU and see what happens and replace parts as needed.

 

[souhiba132]

Only way to really tell is to replace with a known good one, and see what happens.

Oh boy, I guess have no choice but to cross my fingers with this one.
Thanks for the answers guys!